https://github.com/skranz/testex
Test a package by running and comparing examples
https://github.com/skranz/testex
Last synced: 6 months ago
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Test a package by running and comparing examples
- Host: GitHub
- URL: https://github.com/skranz/testex
- Owner: skranz
- Created: 2019-11-30T11:23:29.000Z (over 5 years ago)
- Default Branch: master
- Last Pushed: 2020-10-04T11:44:13.000Z (over 4 years ago)
- Last Synced: 2024-08-13T07:14:26.462Z (10 months ago)
- Language: R
- Size: 138 KB
- Stars: 1
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
[](https://travis-ci.org/skranz/testex)
## Tools for testing packages by comparing results from examples
The standard approach of unit testing, e.g. via [testthat](https://testthat.r-lib.org/) is to write explicit test commands, like
```r
test_that("Distinct roots", {
roots <- real.roots(1, 7, 12)
expect_that( roots, is_a("numeric") )
expect_that( length(roots), equals(2) )
expect_that( roots[1] < roots[2], is_true() )
})
```
Copied from [this](https://www.johndcook.com/blog/2013/06/12/example-of-unit-testing-r-code-with-testthat/) blog entry on testing.
While very useful, writing comprehensive tests is also quite time intensive. While I have not written explicit tests for my packages, they have a lot of examples, partly in separate R files, partly inside vignettes.
If these examples worked correctly in a previous version of my package, one way of testing a new package version is that all those examples again run without error and yield the same results as earlier (unless I changed something on purpose that would cause different results).
The package `testex` shall help to test your package using your examples. Install it from Github via:
```
devools::install_github("skranz/testex")
```
Below is a simple illustration.
```r
# Assume f is a function in your package
f = function(x) {
x
}
# Some example code
code = "
f(1)
f(2)
f(3)
"
library(testex)
# Specify all example sources. Can be files
# or direct code as strings.
sources = testex_sources(ex.text=c(myexample=code))
# Create an example test object by running
# all examples. It uses all objects from
# the global environment and currently loaded
# packages.
et = testex_create(sources)
# You may want to save et somewhere
# saveRDS(et, "example_tests.Rds")
```
Let us mimick a change in the package by changing the function `f`:
```r
f = function(x) {
if (x==2) stop("Error")
x*x
}
# Load old example test
# et = readRDS("example_tests.Rds")
# Evaluate all examples again
# and compare with previous results
res = testex_run(et)
```
You will see the message:
```
Eval myexample
2 issues found when testing examples. See log in
example_test_log.Rmd
```
The created log file `example_test_log.Rmd` will show you where the errors have occured in a human readable form.
The returned list `res` will look like:
```
res
$`num.issues`
[1] 2
$issue.df
# A tibble: 2 x 7
file part call class fun differs error
1 "" myexample numeric f TRUE TRUE
2 "" myexample numeric f TRUE FALSE
$stat.df
# A tibble: 1 x 3
fun differs error
1 f 2 1
```
## Integrating with Travis CI
For an example of how to combine `testex` with [Travis CI](https://docs.travis-ci.com/user/languages/r/), take a look at the github page of my [RelationContracts](https://github.com/skranz/RelationalContracts) package. In particular look at the [.travis.yml](https://github.com/skranz/RelationalContracts/blob/master/.travis.yml) file and the folder [testex](https://github.com/skranz/RelationalContracts/tree/master/testex).
You can also look at the corresponding files on the [testex](https://github.com/skranz/testex) github page, but those might be less clear due to the recursive nature of testing `testex` with `testex`.